Incidence of TSCI in Estonia

The reason why the current study was undertaken is that there is a paucity of studies of TSCI in Eastern Europe and Estonia (Figure 15). Relevant data reflect the level of controlling SCI and point to the need for improving preventable strategies. Neither reduction in the number or severity of TSCI or mortality after TSCI, nor improvements in the care of SCI will be possible if there is no reliable information about the epidemiological scale of SCI.

Paper I shows the high incidence of spinal cord injuries in Estonia. Previous international studies have been mostly hospital based (van Asbeck et al., 2000;

Berg et al., 2011) or limited to adult population (Ahoniemi et al., 2008). To our knowledge, the present study is the first population-based research that included all age groups from all hospitals across the whole country.

The incidence of TSCI differs greatly between countries. The crude in-cidence of TSCI was 39.7 per million in Estonia from 1997 to 2007, which is one of the highest in Europe. Only a Portugal study, which included prehospital mortalities reported higher incidence rate (Martins et al., 1998).

On the other hand, lack of standardised global reporting of aetiology data on TSCI reduces the ability of the data to contribute to specific injury prevention strategies or hypotheses worldwide (Cripps et al., 2011). Until now, only one study group has conducted a comparative research on TSCI in two different countries at the same time (Divanoglou and Levi, 2009). In the second paper we compared the incidence, characteristics and mortality of TSCI in Western Norway and Estonia. Previous population studies have revealed several differences in the lifestyle in the Baltic countries compared to Western Europe, differences that may negatively influence the health status and the risk of trauma (Rekand et al., 2004).

The standardised annual age- and gender adjusted incidence rates were 24.9 and 37.4 in Norway and Estonia, respectively, i.e. 1.5 times higher in Estonia than in Western Norway.

Table 14. Volumes, maximum t-values, centres of gravity and weighted laterality indexes of the right hand and ankle movement representation in the TSCI patients during the first year after injury. Group Hand Study 1Study 2Study 3AnkleStudy 1Study 2Study 3 FWE corrected0.05 0.05 0.050.050.050.05 BA 1-2-3-5 No. of patients with activation6 6 6 3 2 3 VOA ± s.d. (mm3 ) 6960 ± 71368212 ± 111833702 ± 20291985 ± 29386208 ± 54192117 ± 1178 Maximum t-value 9.9 ± 3.010.6± 3.57.9 ±1.37.8 ± 1.711.6 ± 2.57.8 ± 0.6 COG x –40 ± 2–41 ± 5–46 ± 8–37 ± 27–31 ± 2818 ± 38 COG y –30 ± 3–29 ± 3–24 ± 9–31 ± 9–31 ± 18–39 ± 15 COG z 54 ± 353 ± 249 ± 747 ± 1753 ± 1556 ± 11 wLI 0.71 ± 0.120.46 ± 0.260.34 ± 0.320.38 ± 0.380.17 ± 0.590.09 ±0.51 BA 4 No. of patients with activation6 6 6 5 4 4 VOA ± s.d. (mm3 ) 4229 ±3126 4897 ± 54952849 ± 21843516 ± 28284068 ± 50202868 ± 692 Maximum t-value 11.2 ± 3.912.3 ± 4.59.9 ± 3.010.3 ± 3.710.3 ± 4.49.6 ± 2.4 COG x –37 ± 5–38 ± 5–42 ± 8–5 ± 2–6 ± 2–2 ± 3 COG y –22 ± 3–21 ± 3–18 ± 8–23 ± 2–26 ± 3–24 ± 1 COG z 57 ± 456 ± 453 ± 864 ± 465 ±4 63 ± 4 wLI 0.76 ± 0.130.72 ± 0.150.66 ± 0.250.70 ±0.110.63 ± 0.240.42 ± 0.33 BA 6 No. of patients with activation6 6 6 6 5 5 VOA ± s.d. (mm3 ) 16121 ± 1207517583 ± 245489931 ± 97999865 ± 106688259 ± 132295873 ± 3685 Maximum t-value 13.1 ± 3.013.1 ± 4.99.9 ± 2.7 9.6 ± 2.1 8.7 ± 3.3 9.0 ± 2.0 COG x –25 ± 8–24 ± 12–33 ± 16–8 ± 7–7 ± 30 ± 5 COG y –10 ± 4–14 ± 8–10 ± 11–7 ± 3–8 ± 3–6 ± 4 COG z 63 ± 263 ± 457 ± 1664 ± 569 ± 567 ± 5 wLI 0.70 ± 0.130.61 ± 0.190.46 ± 0.240.29 ± 0.200.32 ± 0.200.04 ± 0.34 Abbreviations: FWE, corrected for familywise error; BA, Brodmann area; VOA, volume of activation; s.d., standard deviation; COG, centre of gravity; wLI, weighted laterality index.

Figure 15. Incidence of TSCI in Europe, per million population.

(Ahoniemi et al., 2008; Albert et al., 2009; Biering-Sorensen et al., 1990; Divanoglou et al., 2009; Exner et al., 1997; Hagen et al., 2010a; Kondakov et al., 2002; Knútsdóttir et al., 2012; Martins et al., 1998; O’Connor et al., 2006; Pagliacci et al., 2003; 1998;

Soopramanien, 1994; van Asbeck et al., 2000; van den Berg et al., 2010b)

The first reason for the difference is due to socioeconomic circumstances. Poor-ly managed societal transition to market economy, higher unemployment, in-equalities in wealth, poor regulatory and enforcement mechanisms predispose Eastern Europe and Eurasian countries to high personal burden of injuries (Hyder and Aggarwal, 2009). It has been found that people in low-to-middle outcome countries are 3.6 times more likely to die from injuries (Sethi et al., 2006).

The second explanation is closely related to preventive measures. There has been an extensive focus on prevention of traumas in Norway while less effort has been directed to prevention in Estonia. Campaigns targeting young drivers have reduced the number of injuries among younger people (Lai et al., 2005)

The third explanation is geographical differences. The risk of traumatic

(Dryden et al., 2003). Western Norway is dominated by mountains and fjords, which reduces speeding options. On the other hand, falling from height could be more frequent in these regions. The landscape of Estonia is flatter, allowing motor vehicles to drive at a high speed.

In the first study we found an increasing trend in the incidence from 1999 to 2007 in Estonia. The possible explanation is that the prevention of TSCI was ineffective. Another explanation may be that we missed some cases in the first study years. However, the incidence rates were fluctuating at the beginning of that period (Figure 4). In this connection it should be noted that Hagen and colleagues have reported an increasing trend in the TSCI incidence rates when the study period was longer (Hagen et al., 2010a). Still, no clear explanation has been given yet for this phenomenon.

The strength of the studies in Papers 1 and 2 was the inclusion of the whole Estonian population in the study. Also, several overlapping sources of informa-tion were reviewed to minimize errors and missing cases. Medical records were reviewed even in the smallest local hospitals where patients with TSCI are usually not treated. Thus, we probably missed no cases.

The studies had some limitations. Firstly, we did not include the patients who died before the arrival to hospital. Only three studies by other authors have included fatal cases before hospitalisation so far and have presented higher incidence rates than other studies (Wyndaele and Wyndaele, 2006). A study of prehospital mortality is currently in progress in Estonia. Secondly, we identified the TSCI patients by the diagnostic codes only. However, the list of the ICD-10 codes suggesting a TSCI was expanded to cover spinal fractures at every level in order to obtain more cases. Thirdly, as the study was performed with a retro-spective design available information was probably limited. In order to show trends in TSCI, a prospective register providing full coverage of the population would be needed.

6.2. Risk factors of TSCI

Consistent with previous studies (Ackery et al., 2004; Ahoniemi et al., 2008;

Albert et al., 2005; Berg et al., 2011; Biering-Sørensen et al., 1990; Celani et al., 2001; Chiu et al., 2010; Dincer et al., 1992; Divangolou and Levi, 2009;

Dryden et al., 2003; Espagnaq et al., 2011; Exner and Meinecke, 2010; Hagen et al., 2010a; Jackson et al., 2004; Karacan et al., 2010; Kondakov et al., 2002;

Knútsdóttir et al., 2012; Martins et al., 1998; O’Connor, 2002; O’Connor and Murray, 2006; Pagliacci et al., 2003; Pickett et al., 2006; Soopramanien, 1994;

Surkin et al., 2000; van Asbeck et al., 2000; van den Berg et al., 2010b; Wyn-daele and WynWyn-daele, 2006), men were more prone to TSCI in all age-groups in Estonia. There is no clear explanation why men are at greater risk for TSCI. It has been suggested that women perform risky activities more cautiously than men and therefore may be exposed to lower risk of injury. An international comparative study from 19 European countries found that women drive safer

than men (Golias et al., 2002). This study also showed that men below the age of 55 have the most dangerous driving behavior.

Many developed countries have reported the bimodal distribution of TSCI incidence rates with the second peak after the age of 60 (Berg et al., 2011;

Dryden et al., 2003). This has been explained by the fact that the mean age at the time of injury is increasing because population is aging. The percentage of people older than 65 years is even higher in Estonia than the European region average (European Union, 2010). However, our data did not reveal this bimodal distribution. The incidence was very high in the age-group of 20-29 years in Estonia and declined substantially with increasing age becoming similar to that in other European countries.

In comparing Estonia and Western Norway in the Paper 2, the general population aged 60 years or more is high in both regions. Still, the proportions of TSCI patients in Estonia and in Western Norway are poles apart – young men in Estonia and elderly men in Norway. There is no convincing explanation for that. We may postulate that the elderly in Estonia might be less healthy, functionally less capable and do not take part in potentially dangerous activities.

The latter hypothesis is based on the finding that physical activity is associated with increased longevity (Gulavik et al., 2012). Studies have found people in the Baltic countries to be physically inactive (Pomerleau et al., 2000). For example a study on the lifestyle and sequels of poliomyelitis found that physical activity is lower in Estonia compared with Norway (Rekand et al., 2004). How-ever, intrinsic and also extrinsic risk factors should be taken into consideration.

Alcohol consumption is high in Estonia and alcohol abuse before TSCI was recorded in almost half of the cases in Estonia. Higher percentage of patients had consumed alcohol prior to accident in Estonia compared with Western Norway. Since 2005 the government alcohol policy has become more strict in Estonia and alcohol consumption has decreased since 2008 (Lai and Habicht, 2011). Our study included the cases until 31 December, 2007 and it found no statistically significant decrease in alcohol consumption preceding trauma.

Alcohol abuse is a clear risk factor for TSCI. There is a need for more effective preventive measures concerning alcohol.

6.3. Causes of TSCI

In Europe traffic accidents cause 23 to 72% of all TSCI, with the highest percentage in Central Europe (Cripps et al., 2011; Divangolou and Levi, 2009;

Soopramanien, 1994). The percentages of TSCI due to falls vary between 17 to 49% (Catz et al., 2002; Cripps et al., 2011; van Asbeck et al., 2000). In line with previous studies (Ahoniemi et al., 2008; Hagen et al., 2005; Silberstein and Rabinovich, 1995), falls is the most frequent cause of TSCI in Estonia as well as in Western Norway.

Persons between 20 and 29 years of age are most often injured in traffic

were caused by diving. Consistent with a previous report (European Union, 2010), young healthy men in their early twenties are usually the victims of diving accidents. In Estonia falls became the most prevalent cause of TSCI among persons older than 29 years.

U-shaped association has been found between physical activity and the risk of falling (Chan et al, 2007; Gregg et al., 1998). Although a less active lifestyle is a risk factor for falling, the highly active lifestyle in patients with balance problems as well as coexisting medical problems may predispose the Nor-wegian elderly to falls.

Falls was also the most prevalent external cause of TSCI occurring in the workplace, followed by blows to the vertebral spine. It shows that Estonian workers as well as employers should be better educated regarding safety.

Taking into consideration that TSCI incapacitates a higher proportion of inhabitants in Estonia than in other European countries, preventive measures should be more efficacious in general. The measures should be specifically targeted to the younger age-groups, particularly men.

6.4. Mortality and causes of death after TSCI

Our study is the first research to examine mortality after TSCI in Eastern Europe. As expected, the life expectancy of patients with TSCI was found to be significantly reduced in comparison to the general population. Almost half of the patients died during the first year after TSCI. The risk of death was higher in the group with C1-4 AIS A-C lesions. The rate of SMRs is higher among women and the cause-specific SMRs in Estonia were noted to be extremely high for sepsis and skin-related causes, as well as also significantly increased for other causes including genitourinary disease and suicide. In fact, there is a large discrepancy in life expectancy rates between different survival studies, which can be attributed to some methodological differences. Most of them have excluded patients who die at the scene of the accident, on arrival at the hospital, or during the first days. Many studies have focused on patients in the rehabili-tative phase and have excluded deaths occurring in the acute or sub-acute phase of injury (van den Berg et al., 2010; Soden et al., 2000). Therefore, the mortality rates are considerably variable.

Our results have a number of similarities with the findings of Hagen et al.’s, showing that women and patients younger than 40 years of age at the time of injury have particularly decreased life expectancy (Hagen et al., 2010b). It is noteworthy that so far only Scandinavian countries have reported higher female mortality (Ahoniemi et al., 2011; Hagen et al., 2010b; Hartkopp et al., 1997;

Lidal et al., 2007). However, in our study, gender was not statistically signi-ficant in the Cox proportional hazard modelling. This could be explained by the fact that mortality among men in the general population in Estonia is high, which diminishes differences between the sexes (European Communities, 2009).

Physical changes after TSCI affect the patient emotionally, socially and psychologically. Krause et al. have pointed out that important predictors of mortality are social support, income, psychology and behavioural factors (Krause et al., 2009; Krause et al., 2011). It is worthwhile noting the results from Pentland et al. claiming that women with TSCI feel themselves in iso-lation and have the perception of being forgotten (Pentland et al., 2002). Factors such as these may have an impact on the observed high risk of death in women.

Consistent with earlier studies, the incidence of death in patients with TSCI from septicaemia, respiratory diseases, diseases of urinary system and suicide is significantly higher than in general population (Hagen et al., 2010b; Soden et al., 2000). Soden et al. suggest that TSCI places patients at a considerable risk of suicide (Soden et al., 2000). Suicide generally is also a major issue in Estonia (Värnik, 2012). After the first year, the incidence of suicides increased to 13.8%

among patients with TSCI in Estonia. In contrast to a Finnish study(Ahoniemi et al., 2011), the patients who committed suicide in Estonia were men, and half of them had tetraplegia.

Survival is considered to be strongly related to neurological level and degree of impairment (DeVivo et al., 1999; Middleton et al., 2012; van den Berg et al., 2010). Although in recent years there has been a trend towards improvement in acute phase survival rates, longer term mortality has remained constant (DeVivo, 2007). As might have been expected, we also found a strong relation-ship between neurological level and completeness of injury. During the first year, the mortality risk was significantly higher among the patients with C1-4 injury level, AIS A, B, C, which stabilised thereafter. No significant reduction in the first-year mortality was detected during the follow-up period from 1997 to 2011 in Estonia. This is hard to explain, because progressive economical development and improvements in medical care were taking place in Estonia during the period predicting decline in mortality.

Surprisingly, alcohol consumption before the trauma did not have an effect on early or late mortality in our research. It is plausible that data about regular alcohol drinking, not available in our study, could have influenced the obtained results. Alcohol-attributable mortality is more than 4 times higher for men and more than 3 times higher for women in the Baltic countries (Rehm et al., 2011).

Krause et al. showed that alcohol drinking, especially binge-drinking, is a type of behaviour related to early mortality (Krause et al., 2009). According to this risk factor, and the findings that Estonians engage in binge drinking (McKee and Britton, 1998), we would suggest that alcohol drinking be considered as an important risk factor in Estonia for mortality after TSCI.

Limitations of the mortality study include insufficient information on the patients’ death certificates regarding the causes of death. This has also been a noted problem in other studies (Middleton et al., 2012). Some SMRs have been calculated on the basis of few deaths and should therefore be interpreted with caution. The risk factors were collected during the first hospitalisation and were not assessed later. Chronic diseases as a potential risk factor for death were not

retrospective and identification of patients took place according to the diag-nostic codes. Patients who died before arrival at the hospital were excluded, which may have induced underestimation of the mortality rates.

Despite the above-mentioned limitations, it is a unique study focused on all age-groups in the Estonian population. Patients with TSCI were sought retro-spectively from every Estonian hospital, and the list of ICD-10 codes suggesting a TSCI was expanded to include spinal fractures at every level in order to gain more cases (Table 1).The overall SMR confirm that mortality is high among patients with TSCI in Estonia. In the current study we identified that age at the time of injury, C1-C4 neurological level and completeness of injury, as well as concomitant injuries, are the risk factors for death during the first two years after the injury. Later, only age, completeness of trauma and cause of TCSI are significant risk factors for mortality.

In conclusion, the main causes of death among patients with TSCI are cardiovascular diseases, pneumonias, genitourinary tract infections and in-fections related to pressure areas, and suicide. The overall life expectancy of the patients is significantly decreased compared with general population. The assertion by Hitzig et al. that TSCI represents a model of premature aging (Hitzig et al., 2011) affecting multiple body structures and functions, should lead us to a holistic focus on multi-system management addressing all modifiable risk factors and their potential interactions.